An artist's montage of the Phoenix probe and its landing. True to the picture, the probe landed intact. (Source: NASA/JPL-Caltech/University of Arizona)

The first images from the Phoenix spacecraft have been send back, confirming polygonal ground patterns resembling those on permafrost ground on Earth. (color is false) (Source: NASA/JPL-Caltech/University of Arizona)

No metric metric conversion or other snafus could foil the landing of the Phoenix lander

The lander promises to not only prepare for the ongoing efforts to send humans to Mars, but also will further the investigation of the possibility that life once existed on Mars. Before it could complete its mission, though, it had to land. After months of travel through the dark depths of space, it reached the fringe of Mars' atmosphere and began a plunge referred to as "seven minutes of terror" by NASA. The seven minute entry has been a punishing one on past satellites -- of the 11 objects which various nations have tried to land on Mars, only 5 survived.

Safely landing requires aeroshell breaking, using a heat resistant shield to create friction with the atmosphere slowing its descent from catastrophic speeds. The side effect is the shield heats to thousands of degrees, increasing the chance of failures. After sufficiently reducing the speed, a parachute is deployed. This is yet another phase prone to past failures. Finally, the probe must use its retrorockets to gently touch down the surface, to prevent impact damage.

Unfortunately there's no possibility for an Earth-driven landing sequence -- Mars is 15 minutes away from the Earth in radio signal time. So the craft had to land autonomously. Shortly before 5:00 pm PDT on Sunday, NASA scientists breathed a collective sigh of relief when they received thumbs up signals from the satellite.

Barry Goldstein, Phoenix project manager at NASA's Jet Propulsion Laboratory said in a statement Sunday that while the most difficult part perhaps -- landing -- had been conquered, challenges lay ahead. Said Goldstein, "We've passed the hardest part and we're breathing again, but we still need to see that Phoenix has opened its solar arrays and begun generating power."

Then late on Sunday, after two hours of silence, the lander started sending back its first pictures, which confirmed that its solar arrays needed for the mission's energy supply had unfolded properly, and masts for the stereo camera and weather station had swung into vertical position.

Ed Sedivy, Phoenix program manager at Lockheed Martin Space Systems Company enthusiastically stated, "Phoenix is an amazing machine, and it was built and flown by an amazing team. Through the entire entry, descent and landing phase, it performed flawlessly. The spacecraft stayed in contact with Earth during that critical period, and we received a lot of data about its health and performance. I'm happy to report it's in great shape."

The spacecraft landed in a crater in the polar region, which is expected to hold permafrost. The probe carries instruments to "taste and sniff" the polar ice. Peter Smith of the University of Arizona, Tucson, principal investigator for the Phoenix mission commented on the initial pictures stating, "We see the lack of rocks that we expected, we see the polygons that we saw from space, we don't see ice on the surface, but we think we will see it beneath the surface. It looks great to me."

The next major milestone will be the use of the lander's 7.7 foot robotic arm, which will occur on Tuesday. The arm contains instruments to dig into the soil and test the permafrost to see if it ever melts and also to see if it has certain chemicals necessary for life as we know it.

The Phoenix lander's hardware, true to its name rose from the ashes of a discarded program. In 1999 a lander built using most of the same hardware was lost during landing. This caused a second launch, scheduled for 2001, to be cancelled and the additional hardware built for it to be put in storage. NASA put the hardware to new use in 2002 for the Phoenix lander, following increased interest in the possibility of life on Mars and human mars exploration.

The mission is truly an international effort. Outside the U.S. many partners including Canadian Space Agency; the University of Neuchatel, Switzerland; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; the European Space Agency; and the Finnish Meteorological Institute, have contributed to the project.

Comments

Threshold

Username

Password

remember me

This article is over a month old, voting and posting comments is disabled